ISTD

Maximum Ion Suppression (%)

Median Ion Suppression (%)

Maximum Ion Enhancement (%)

Morphine-D6

76.1

39.2

10

Oxymorphone-D3

63.5

29.1

16.3

Hydromorphone-D6

72.6

27.2

10.3

Amphetamine-D5

47.8

8.7

7.7

Codeine-D6

49.1

17.4

9.2

Oxycodone-D6

57.2

23

13.3

Methamphetamine-D5

79.4

8.9

3.4

Oxycodone-D6

57.2

23

13.3

Hydrocodone-D6

55.4

13.3

9.3

Methamphetamine-D5

79.4

8.9

3.4

Hydrocodone-D6

55.4

13.3

9.3

6-Acetylmorphine-D6

52.8

5.7

14

Ritalinic acid-D10

56.2

7.9

14.7

7-NH2-clonazepam-D7

88.3

37.9

16.3

Ketamine-D4

56.9

5.6

8.9

Benzoylecgonine-D3

59.4

9.6

6.2

Ketamine-D4

56.9

5.6

8.9

Norfentanyl-D5

56.9

10

13.2

Methylphenidate-D9

48.3

5.6

5.7

Tramadol-13CD3

53.1

5.1

6.4

Tramadol-13CD3

53.1

5.1

6.4

Normeperidine-D4

42.8

6

3.9

Meperidine-D4

44.2

4.9

5

Meprobamate-D7

57

16.8

8.4

Norbuprenorphine-D3

49.8

16.6

13.2

Phencyclidine-D5

28.3

3.6

7.3

Fentanyl-D5

24.9

3.3

4.5

Doxepin-D3

33.8

7

9.2

EDDP-D3

26.1

2.7

4.9

Buprenorphine-D4

41

5.4

4.6

Amitriptyline-D3

31.9

4.2

8.6

Amitriptyline-D3

31.9

4.2

8.6

Amitriptyline-D3

31.9

4.2

8.6

α-OH-alprazolam-D5

22.8

3

16.8

Amitriptyline-D3

31.9

4.2

8.6

Oxazepam-D5

31.4

15.2

12.2

Propoxyphene-D5

30.8

2.6

5.6

Amitriptyline-D3

31.9

4.2

8.6

Propoxyphene-D5

30.8

2.6

5.6

Methadone-D3

19.4

2.9

5.5

Oxazepam-D5

31.4

15.2

12.2

Temazepam-D5

27.5

11.7

9.9

Carisoprodol-D7

40.6

9.1

6.8

Temazepam-D5

27.5

11.7

9.9

The test analytes are listed in the order of their elution. Ion suppression and ion enhancement were evaluated by tabulating the deuterated internal standard (ISTD) responses within 96-well plate batches. The reference (i.e. no ion suppression) values for ISTD area responses were defined as the mean ISTD area responses for the eight blank specimens included in each batch. Maximum ion suppression (%) for each ISTD was calculated using the formula:
100 – (mean blank ISTD area – minimum intra-batch ISTD area * 100)
Median ion suppression (%) for each ISTD was calculated using the formula:
100 – (mean blank ISTD response – median intra-batch ISTD area * 100)
Maximum ion enhancement was calculated using the formula:
(Maximum intra-batch ISTD area – mean blank ISTD area) – 100

Table 3: Ion suppression as a function of elution.